Non-volatile memory devices are widely used in various kinds of electronic products such as mobile telephones, etc. One type of non-volatile memory that has become popular is what is commonly referred to as NOR type flash memory. It is recognized that in conventional NOR flash memory, the metal contact employed in source/drain regions may use a significant area of the integrated circuit. Accordingly, one approach, sometimes referred to as buried bit line, has been used to avoid the formation of contacts in NOR type flash memory.
Non-volatile memories are also discussed in, for example, U.S. Patent Publication No. 2004/0169238 A1 to Lee et al., U.S. Patent Publication No. 2006/0180851 A1 to Lee et al., U.S. Pat. No. 5,526,307 to Yiu et al., U.S. Pat. No. 6,858,906 B2 to Lee et al. and U.S. Pat. No. 7,072,214 B2 to Jeong et al.